Add GitHub Actions CI/CD for SAM stack deployment

[Copilot]

Automates deployment of AWS SAM stacks (path-tracer and preprocessor Lambda functions) using GitHub Actions with OIDC authentication.

Workflows

deploy-sam.yml

• Manual-only deployment via workflow_dispatch (no auto-deploy on push)
• Configurable stack name and environment (prod/staging)
• OIDC-based AWS authentication (no long-lived credentials)
• Builds Docker images and deploys to Lambda via SAM CLI

validate-sam.yml

• Runs on PRs touching SAM templates
• Validates template syntax and performs build dry-runs

Setup Required

AWS Resources:

• OIDC identity provider: token.actions.githubusercontent.com
• IAM role with least-privilege policies (see .github/workflows/README.md)
• S3 bucket for artifacts, ECR repository for images

GitHub Secrets:

AWS_ROLE_ARN: arn:aws:iam::123456789012:role/GitHubActionsDeployRole
SAM_ARTIFACTS_BUCKET: distributed-path-tracer-artifacts
ECR_REPOSITORY: 123456789012.dkr.ecr.us-east-1.amazonaws.com/distributed-path-tracer

Deploy by running the workflow manually under Actions → Deploy SAM Application.

Original prompt

Review my CDK code.

Use github actions to deploy my cdk stacks

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